Reserve officers are citizen volunteers who have an interest in law enforcement but have careers in other fields. Reserve officers must attend state-mandated training in order to be a reserve officer. These reserve officers attend this training on their own time and at their own expense.

There are three levels of reserve police officers. The entry level is called a "Level III" reserve police officer. This level requires 162 hours of state-mandated training. With this training the level III reserve officer may perform limited support duties such as traffic control, security at parades and sporting events, parking enforcement, etc. The level III reserve officer must always be under the direct supervision of a full-time police officer. A "Level II" reserve officer requires 368 hours of state-mandated training. With this training, the level II reserve officer may perform general law enforcement duties while under the direct supervision of a full-time police officer. A "Level I" reserve officer requires 664 hours of state-mandated training. With this training the level I reserve officer can do general law enforcement duties and can operate independently as a police officer.

In addition, all Union City reserve police officers must complete the 400 hour Union City Police Department Field Training Program. Reserve officers must also complete twenty-four hours of ongoing professional training every two years on their own time.

All Union City Police reserve officers must pass the Union City Police Department background examination and are required to work 20 hours per month. Generally, most of that time is with the Patrol Section .